Ride a bicycle. Seriously, there are no options that will be hassle-free since BMW is not going to give you a loaner while you wait for your new car to arrive. In my opinion, your best option is to keep your Accord and drive it to the ground. It is a great family hauler and will you save mileage on your new M3. I have a 2003 Acccord with 170K miles and it is till running strong.